---

All answers having "Difficulty" as clue:

3 Character Answers:

---

ADO

RUB



4 Character Answers:

---

HOLE

NEED

SNAG



5 Character Answers:

---

NODUS

RIGOR

TRIAL



6 Character Answers:

---

SCRAPE

STRAIT



7 Character Answers:

---

DILEMMA

PROBLEM

TROUBLE



8 Character Answers:

---

HARDSHIP

HOTWATER